The present invention is generally in the field of pharmaceutical formulations, and more particularly related to methods and compositions for nasally administering antihistamines.
Azelastine hydrochloride is a potent, long acting antihistamine currently administered via the intranasal route in an aqueous solution for the treatment of the symptoms of allergic rhinitis, such as rhinorrhea, sneezing and nasal pruritus. While it is efficacious when administered in this fashion, the liquid nasal spray imparts a long lasting, very bitter taste. Furthermore, somnolence has been reported in some patients taking azelastine. Somnolence is a common unwanted side effect of most antihistamines and is dose related. Azelastine is orally absorbed. Therefore, any azelastine that penetrates the back of the throat and the mouth is orally absorbed, contributing to the central nervous system effects of somnolence and also accounts for the bitter taste experienced by patients.
It would be clearly desirable to have a formulation of azelastine that would not impart a bitter taste and would not produce somnolence.
It is therefore an object of the present invention to provide an antihistamine formulation that does not impart a bitter taste or produce somnolence.
It is another object of the present invention to provide a formulation of antihistamines that provides only local or region effects of the antihistamine, not systemic effects.